The long-term objective is to improve medical imaging quality, thereby improving detection, diagnosis, and therapy for a number of human health diseases. The specific aim of this research is to fabricate advanced high-resolution collimators for nuclear medicine imaging. An innovative fabrication technology will be used to produce advanced high-resolution collimators made from improved materials. The combination of a new fabrication method and new collimator materials offer important advantages in terms of design flexibility and performance over current collimator fabrication techniques. This is an enabling technology. Most importantly, it has the potential to allow very high-quality collimators to be produced at a relatively low cost. Phase I will demonstrate technical feasibility by fabricating prototype low energy high-resolution (LEHR) collimators employing a dense (-11 g/cc) composite material, and comparing their dimensional accuracy and imaging performance against state-of-the-art LEHR collimators commercially available. Phase II will refine the technological approach and extend the technology to other elements in an 'aligned' detector system including collimator, scintillator detector array, and optical interface elements. Potential commercial applications include nuclear medicine (small and large format cameras), computed tomography, mammography, as well as non-medical applications such as astrophysics, non-destructive testing, and security scanners.